Lenkinski R E, Stephens R L, Krishna N R
Biochemistry. 1981 May 26;20(11):3122-6. doi: 10.1021/bi00514a021.
The peptide amide hydrogen exchange rate of human angiotensin II in H2O have been measured at room temperature by the transfer of solvent saturation method. The data are consistent with the assumption of a highly motile dynamic equilibrium between folded and highly solvated conformations. The NH of His6 is observed to exchange more slowly than predicted, suggesting that it is a participant in an internal hydrogen bond. Several models previously suggested in the literature for the conformation of the peptide in aqueous solution are examined, and most are found to be inconsistent with the exchange data. Evidence in support of a structure for the Ile5-His6 fragment of the hormone involving a C7eq-C5 bend is presented.
通过溶剂饱和转移法在室温下测定了人血管紧张素 II 在 H2O 中的肽酰胺氢交换速率。数据与折叠构象和高度溶剂化构象之间存在高度动态平衡的假设一致。观察到 His6 的 NH 交换比预测的要慢，这表明它参与了一个内部氢键。研究了文献中先前提出的几种该肽在水溶液中的构象模型，发现大多数与交换数据不一致。提出了支持该激素的 Ile5-His6 片段具有涉及 C7eq-C5 弯曲结构的证据。
